Photographic bleaching and antifogging agents

ABSTRACT

AMINOMETHYLQUINONES AND SALTS THEREOF HAVING THE GENERAL FORMULA:   R1,(A-CH2-)N-P-BENZOQUINONE (I)   R1,(A-CH2-)N-O-BENZOQUINONE (II)   WHEREIN R1 REPRESENTS HYDROGEN, AN ALKYL GROUP (INCLUDING AN ARALKYL GROUP), AN ARYL GROUP OR A-CH2A GROUP; N REPRESENTS AN INTEGER OF FROM 1 TO 3; A REPRESENTS ANY ONE OF THE GROUPS:-NHR2HX.   -N(-R3)(-R4), -N(-R3)(-R4).HX AND -N+(-R3)(-R4)(-R5).X(-)   R2,R3 AND R4 EACH REPRESENT AN ALKYL GROUP (INCLUDING AN ARALKYL GROUP), AN ALKENYL GROUP, AN ARYL GROUP, ETC. OR R3 AND R4 WHEN TAKEN IN COMBINATION WITH THE NITROGEN ATOM TO WHICH THEY ARE ATTACHED REPRESENT A MONOVALENT, HETEROCYCLIC GROUP; R5 REPRESENTS AN ALKYL GROUP INCLUDING AN ARALKYL GROUP; AND X REPRESENTS AN ANION; WITH THE PROVISION THAT EACH-(CH2A) GROUP IS SUBSTITUTED AT A POSITION ORTHO TO AN OXO GROUP ON THE QUINONE RING; ARE USEFUL AS BLEACHING AGENTS AND AS FOG INHIBITING AGENTS.

United States Patent Int. Cl. G03c 1/34 US. Cl. 96-109 9 Claims ABSTRACTOF THE DISCLOSURE Aminomethylquinones and salts thereof having thegeneral formula:

R (CHzAh or R wherein R represents hydrogen, an alkyl group (includingan aralkyl group), an aryl group or a -CH A group; n represents aninteger of from 1 to 3; A represents any one of the groups: --NHR -HX,

. R HX and ii n -x R R and R each represent an alkyl group (including anaralkyl group), an alkenyl group, an aryl group, etc. or R and R whentaken in combination with the nitrogen atom to which they are attachedrepresent a monovalent, heterocyclic group; R represents an alkyl groupincluding an aralkyl group; and X represents an anion; with theprovision that each -(CH A) group is substituted at a position ortho toan oxo group on the quinone ring; are useful as bleaching agents and asfog inhibiting agents.

This invention relates to novel aminomethylquinone compounds and saltsthereof, and to the art of photography. More particularly, thisinvention relates to aminomethylquinones and the acid salts andquaternary ammonium salts of such aminomethylquinones, and to the use ofsuch compounds and salts as photographic bleaching agents for silver andas fog inhibiting agents.

In photographic color processes, such as those in which a colored imageis formed by development with an aromatic primary amine developing agentin the presence of a coupler compound, the silver images formed in thedevelopment are generally present in the emulsion layer after the dyeimages are formed. These silver images are generally removed byconverting them to a silver salt which is soluble or which is removed bya silver salt solvent, such as, an alkali metal thiosulfate.

A bleach bath containing quinone, acid and an organic solvent has beenused to convert silver images to a silver salt in the presence of adeveloped dye image. However, this bath cannot be used in the finalstages of a color process because it destroys the dyes, as well asconverts the silver to a silver salt. In addition, while compounds suchas quinone are known to bleach silver in acidic solution, such compoundssuffer from the fact that they are water-insoluble and also insoluble indilute mineral acids. Prior art acid quinone bleach solutions releasetoxic vapors.

During development of a silver halide emulsion, small amounts of silverhalide tend to be reduced to metallic silver, even though they have notbeen light exposed and have no latent image. This reduction of silverion to silver produces a background fog which is more specificallyreferred to as chemical fog.

Chemical fog, apparent in most silver halide systems, has been reducedby prior art methods of processing exposed silver halide material in thepresence of compounds which restrict development of unexposed silverhalide. Such compounds may be incorporated in the silver halide emulsionor in the processing solutions for developing such silver halideemulsions. Fog inhibiting compounds have been found which have achemical fog inhibiting effect on emulsions which have been subjected tohigh temperature and high humidity conditions (emulsion stabilizers),and on emulsions which have not been exposed to adverse storageconditions (antifoggants). It would be desirable to provide a new classof fog inhibiting agents.

It is therefore an object of the present invention to provide novelbleaching agents for bleaching silver images in the presence ofcolor-developed dye images.

Another object of the present invention is to provide a bleach bath thatdoes not release toxic fumes and is comprised of a novel class ofwater-soluble, photographic bleaching agents for silver.

Still another object of the present invention is to provide a method forconverting silver images to a silver salt without destroying the dyeimages in the emulsion layer.

Another object of this invention is to provide a novel class offog-inhibiting agents for photographic silver halide emulsions.

A further object of the invention is to provide a photographic elementhaving incorporated therein a fog inhibiting agent.

These and other objects of the present invention are accomplished byproviding photographic bleaching agents and fog inhibiting agentsconsisting of aminomethylquinones and salts thereof having the followinggeneral formula:

( 0 (II) 0 II I! o R1 (011m) or R1 I J (JHZA n wherein R representshydrogen, an alkyl group (including an aralkyl group), an aryl group ora -CH A group; n represents an integer of from 1 to 3; A represents anyone of the groups: NHR -HX,

R R and R each represent an alkyl group (including an aralkyl group), analkenyl group, an aryl group or R and R represent the nonmetallic atomswhich when taken in combination with the nitrogen atom to which they areattached form a monovalent, heterocyclic group; R represents an alkylgroup including an aralkyl group; and X represents an anion; with theprovision that each (CH A) group is substituted at a position ortho toan oxo group on the quinone ring.

The foregoing aminomethyl substituted pand o-quinones and their saltsare desirably employed as bleaching agents in photographic silver bleachsolutions. The aminomethylquinones of the present invention are solublein water and are soluble in dilute acid solutions. Thus, the compoundsof the present invention are more easily and effectively employed assilver bleaching agents than are previous bleaching agents, such as,water-insoluble quinones.

In addition, the aminomethylquinones of the present invention areadvantageously incorporated in photographic silver halide emulsions toprovide a high degree of fog inhibition.

Representative R groups in Formulas I and II include hydrogen, an alkylgroup having from 1 to 25 carbon atoms, e.g., methyl, ethyl, propyl,isopropyl, butyl, hexyl, cyclohexyl, decyl, dodecyl, octadecyl, docosyl,etc., a hydroxyalkyl group, e.g., fl-hydroxyethyl, w-hydroxybutyl, etc.,an alkoxyalkyl group, e.g., B-methoxyethyl, w-butoxybutyl, etc., acarboxyalkyl group, e.g., B-carboxyethyl, w-carboxybutyl, etc., asulfoalkyl group, e.g., p-sulfoethyl, w-sulfobutyl, etc., a'sulfatoalkyl group, e.g., B-sulfatoethyl, w-sulfatobutyl, etc., anacyloxyalkyl group, e.g., B-acetoxyethyl, 'y-acetoxypropyl,w-butyryloxybutyl, etc., an alkoxycarbonylalkyl group, e.g.,fi-methoxycarbonylethyl, w-ethoxycarbonylbutyl, etc., and an aralkylgroup, e.g., benzyl, phenethyl, etc.; an aryl group, e.g., a phenylgroup (e.g., phenyl, tolyl, methoxyphenyl, chlorophenyl, bromophenyl,etc.) and a naphthyl group (e.g. a-naphthyl, fl-naphthyl, etc.); and anaminomethyl group (e.g., dirnethylaminomethyl, pyrrolidinomethyl,morpholinomethyl, etc.).

Representative R R and R groups in Formulas I and II include those alkylgroups and aryl groups which are representative of R and in addition,include an alkenyl group, e.g., an allyl group, e.g., allyl, methallyl,Z-butenyl, etc., a l-alkenyl group, e.g., a l-propenyl, e.g.,l-propenyl, l-butenyl, etc. and R and R (in Formulas I and II representthe nonmetallic atoms which when taken in combination with the nitrogenatom to which they are attached form monovalent, heterocyclic groupsincluding:

-N/ N k, N/ -N NkHa and the like.

Representative R groups in Formulas I and II include those alkyl groupsrepresentative of R R R and R X, in Formulas I and II, represents anacid anion, e.g., chloride, bromide, iodide, nitrate, thiocyanate,sulfamate, perchlorate, p-toluenesulfonate, methyl sulfate, ethylsulfate, etc.

The aminomethylquinones and their salts are advantageously prepared byfirst forming the corresponding hydroquinones and catechols employingthe Mannich condensation, for example, as follows:

on memo mum-r @(ommu CH2N R2 EN 0 RN 0 Hz (in excess) The free base isproduced by neutralizing the acid salt with, for example, ammoniumhydroxide or sodium b1- carbonate solution:

CH NRQ ZH O 2NH4NO3 BENCH:

The quaternary methylammonium quinones are prepared by reacting theaminomethyl hydroquinone with methyl-p-toluene sulfonate (MePTS) andsubsequently oxidizing the resulting material with concentrated nitricacid, for example:

Suitable quaternizing agents that are used include the dialkyl sulfates,the alkyl halides, the aralkyl halides, the alkyl esters of arylsulfonic acids, etc. Specific quaternizing agents include, for example,dimethyl sulfate, diethyl sulfate, dipropyl sulfate, dibutyl sulfate,ethyl bromide, ethyl chloride, methyl iodide, ethyl iodide, n-butyliodide, benzyl chloride, benzyl bromide, methyl-p-toluene sulfonate,butyl-p-toluene sulfonate and ethyl benzenesulfonate. 1

As previously mentioned, the present aminomethylquiones and salts areadvantageously employed as silver bleaching agents and as'fog inhibitingagents. The aminomethylquinones are advantageously employed as foginhibiting agents over a wide range of concentrations. The

optimum amount of a particular aminomethylquinone or evolution ofnitrogen dioxide fumes subsides and all of salt will vary somewhat fromemulsionto..emulsiomand the.hydroquinone dissolves. The reaction mixtureis poured from aminomethylquinone to aminomethylquinone The into oneliter of cold ethanol. A yield of 82 percent of specific optimum amountto be incorporated in an emul- Compound 1,2,5-bis(piperidinomethyl)-p-quinone dinision is determined for anyparticular emulsion by running tric acid salt, M.P. 183-185 C. isobtained.

a series of tests in which the quantity-of.aminomethyl-..-.AnalysinTCalcd. (percent): C, 50.5; H, 6.6;.N, 13.1.

quinone is varied over a given range. For example, a typical amount ofaminomethylquinone is in the range from about .005 g. to about 2.0 g. ofthe aminomethylquinone per mole of silver halide.

Likewise, the concentration of aminomethylquinone employed as a silverbleaching agent is advantageously varied over a wide range, anddetermination of the optimum concentration is well within the skill ofthose work- I Found (percent): C, 50.2; H, 6.8; N, 12.4.

Compounds 2-8 The 2,5-bis(aminomethyl)quinone-nitric acid salts of theexample in the following table are prepared according to the proceduresubstantially as described for Com- TABLE I Analysis of" MeltingCalculated Found Percent point,

.... ..N(CH1)1 78 169-170 41.4 5.8 10.1 41.8 as 15.0

s N(C2H5)1 171-172 47.5 7.0 13.9 47.8 7.5 13.8

1 Decomposition.

ing in the art. Thus, for example, between about 0.1 and about 1.0 moleof aminomethylquinone per liter of aqueous bleach solutionisadyantageously employed.

The following syntheses of representative compounds are included for afurther understanding of our invention:

"Compound 1 Three moles of piperidinepare added slowly to a solutioncomprising three moles of paraformaldehyde and 500 ml. of isopropanol.The mixture is warmed with care on a steam bath while 1 mole ofhydroquinone and 500 ml. of isopropanol are added. Heating on a steambath is continued for 4 to 6 hours during which time white solids areprecipitated. After removal of a portion of the solvent, the solids arerfiltered, washed with ether and dried. Fifty grams of the2,5-bis(piperidinomethyl)hydroquinone formed 'isadded slowly to 200 ml.of cold concentrated nitric acid. The mixture is stirred until the HaAACH

" {Them 11 I I Analysis ot 7 -Melting Calculated Found Y Percent point,A yield "o. o" H N o" H N- Compound No.: a I

14 -N(CH3), 59 45-50 64.8 8.2 12.6 63.8 8.6 13.6 15 N(C4H5)4 99 168-17069.0 9.4 10.1 68.5 9.4 9.5

Compounds 16-21 In order to prepare the quinones of Table III, below;

""The results-are set forth in the following Table III,

twenty grams of a 2,5-bis-(N-methylaminomethyl)hydrobelow:

TABLE III ,7

- 7 I Analysis of- I Melting Calculated Found 9 Percent point, -A Xyield C. 0 H N S O H N S Compound Number:

16 CH3 N03 80 193-194 52.3 7.5 12.2 51.9 7.1 12.2

17 CH8 N01 96 171-172 46.8 6.6 11.9 46.6 6.4 11.8

l 18 -CH3 C1H1s'0'a 65 145 59.4 6.6 4.3 9.9 58.9 6.3 4.2 9.6

19 0H3 mor 64 171-172 40.1 6.1 17.0 .39.8 6.2 17.2

\/ -N N(CH9)2 11192 01111803 infuse-18561.1 7.4 3.8. 61.3 7.4 41.--.--

l Decomposition.

quinone-bis-p-toluenesulfonate are mixed with 20 mls. g. Compoundsp2228.

of concentrated nitric acid. Thirty mls. of ethanolare added to insurecomplete solution of the. hydroquinone derivative and a completereaction. The product is precipitated by addition of 250 mls. of ethylacetate, filtered and washed with ethyl acetate and dried. Thisprocedure is employed with the appropriate2,5-bis(N-methylaminomethyl-fifp-henyl Lcat'echol' swam/(ps7. fromreaction methyl) hydroquinone-bis-p-toluenesulfonatesto 'maketliecorresponding quinone Compounds 1 62l having the following formula:

CHzA

olution with the to,

60 A mixture of*72 grams of-paraf o'rr'naldehyde, one liter is opropanolond 2:4'im0les of pipefidine 'is'heated on a steam bath until 'itbecomes homogeneous. 372 grams of phenyl catechol are addedtothe-gsolution. The mixture is refluxed for 15 minutes, during whichtimelh 3-aminomixtu'reiAfter cooling, the solid precipitate iscollected, .washedwith etherarid driedfOne-t'e'rith of a mole of'thea-minometh'yl '5j-phenyl catecholis slurriedfin cold etee onegonaddition ofunitri'c'acidfthe catechol 'goes into ftionfof. a' deep-redsolution. Forther'addition "of V c-"acidcausesjhe precipitate "of asolid .material '(Co pound 2 2)'whicl1 is filtered, washed with cold;aceto' 'd dried under vacuumf'Ihe'foregoing procedure is repeated,employing various 3 aminomethyl-S-phefiYl catechols, resulting 'inCompounds 23 following for- 10 i.e., Compounds 29 and 31, respectively,are precipitated and crystallized by alternate additions anddecantations of an acetone-ligroin (1:5) mixture. The 3-azabicyclo-(3.2.2)nonane derivative, i.e., Compound 32, is isolated readily fromthe reaction mixture when acetone is employed as a reaction solvent. Thepiperidine derivative, i.e., Compound 30, is obtained from the reactionmixture by drying under vacuum and the residue is isolated with- AC Hout further purification. The resulting Compounds 29-32 2 :HNOs conformto the formula.

ll (3am 11011 0 '2HN03 112A The results are set forth in Table V, below:

TABLEV Analysis of- Melting Calculated Found Percent point, -A yield C.0 H N c H N Compound Numberz' The results are set forth in Table IV,below:

TABLE IV Analysis of Melting Calculated Found Percent point, -A yieldC.CHNCHN Compound No.:

27 N(CH3)2 72' 158 57.6 5.5 9.6 58.1 5.3 6.6 28 -..N(C2H5)2 61 145 61.56.1 8.4 61.8 6.1 8.3

1 Decomposition.

Compounds 29-32 Compounds 33-35 Various 3,6-bis(aminomethyl) oquinone-nitric acid salts are prepared in a manner identical to theprocedure employed in preparing the 2,5-bis(aminomethyl)quinonenitricacid salts, such as, Compounds 1 and 2. The resulting salts have theformula:

2HNOa -CH2A TABLE VI Analysis of- Melting Calculated Found point, -A. 0.0 H N 0 H N Compound Number:

l Decomposition;

Compounds 36-46 N-substituted aminomethylquinones having the formula:

An N-substituted aminomethylhydroquinone hydrochloride salt in an amountof 5 grams is added'to mls." of concentrated nitric acid which ismaintained cold by an ice-water bath. The colorless solids go intosolution with the formation of a yellow color and the evolution ofnitrogen dioxide gas. The reaction mixture is allowed to stand forminutes and is then treated with a 1:1 isopropyl alcohol-methyl ethylketone mixture that had been previously chilled in a Dry-Ice-acetonebath. The precipitated compounds are collected by filtration and driedunder vacuum. The sample is recrystallized from absolute ethanol. Thisprocedure is employed in the preparation of each of the compounds of thepresent invention as set forth in Table VII, below:

Compound 47 A mixture of 5.35 moles of morpholine, 5.35 moles ofparaforrnaldehyde, 700 ml. of benzene and 700 ml. of2-(2-ethoxyethoxy)ethanol is heated and 500 ml. of distillate removed.One mole of hydroquinone in 350 ml. of methanol is then slowly added tothe heated mixture and distillate again removed until the refluxtemperature reaches C. The reaction mixture is refluxed for twentyhours, cooled, and the tetrakis(morpholino)hydroquinone crystals formedare separated and washed with ether to yield 280 g. with a melting pointof 254-257 C. After recrystallization from 2-(2-ethoxyethoxy)ethanol,the tetrakis (morpholino)hydroquinone has a melting point of 256-257" C.Fifty grams of the recrystallized tetrakis(morpholino)hydroquinoneare'added slowly to 200 ml. of cold concentrated nitric acid. Themixture is stirred until the evolution of nitrogen dioxide fumessubsides and all of the hydroquinone derivative has dissolved. Thereaction'mixture is poured into'one liter of cold ethanol. Thetetrakis(morpholino)-p-quinone nitric acid salt that precipitates isseparated from the mixture by filtration and the salt is washed with'ethanol. Compound 47, i.e., tetrakis(morpholino)-p-quinone prepared byneutralizing the acid salt with an aqueous sodium bicarbonate solution,filtering the solid product from the reaction mixture andrecrystallizing from ethyl acetate has a melting point of 168 C. dec.

TABLE VII Analysis 01- Melting Calculated Found Percent point R R yield0.) C H N C H N m ouud number:

Co 3% -C(CH3) -CZH 43. 9 I 151-152 54.9 7.1 9.9 54 5 7. 0 9.5

37. -C(CH C H -n 75.4 159-160 56.4 7.4 9.4 56.3 7.4 9.7 38. C(CH-C4Hq-1l 87.6 137-138 57.7 7.7 9.0 57.5 7.8 8.0 39 -C(CH -CHz-C5H5 82.7168-169 62.4 6.4 8.1 62.1 6.4 7.9 40- C 3 CH3 96.6 -151 47.4 5.3 12.346.9 5.4 12.7 41--- -CH -C2H5 77.9 162-163 49.6 5.8 11.6 49.2 5.8 11.442." CH -C;H1-n 95.2 167-168 51.6 6.3 10.9 51.3 6.5 10.7 43... .CH;,-CH(CH3)2 85.7 148-149 51.6 6.3 10.9 51.5 6.2 10.8 44 CH 4Hq-I1 89.8162-163 53.3 6.7 10.4 53.1 6.4 10.7 45. OH;; CH2C0H5 75.3 165-166 59.25.3 9.2 59.1 5.2 9.0 46 -C1gH31 -CH3 73.0 90-95 66.9 9.9 6.0 66.6 10.06.6

Analysis.Calcd. (percent): C, 61.4; H, 8.2. Found (percent): C, 61.4; H,7.9.

Our compounds of Formulas I and II are advantageously incorporated insilver halide emulsion layers as an antifogging agent. Emulsionscontaining our antifoggants are advantageously used in a wide variety ofphotographic elements of the black-and-white types and of themultilayer, multicolor types. The antifogging agent is advantageouslyadded as a solution in a suitable solvent to the silver halide emulsionas an addenda during the time after the emulsion is washed (if it iswashed) and just prior to coating. Our compounds are advantageouslyadded in the concentration range from about 0.005 g. to about 2.0 g. permole of silver and preferably in the range of from about 0.01 g. toabout 1.0 g. per mole of silver.

The silver halide emulsions used in our invention comprise silverchloride, silver bromide, silver bromoiodide, silver chlorobromoiodideor mixtures thereof. The emulsions range from coarse grain to fine grainand are prepared by any of the well-known procedures. Surface imageemulsions, internal image emulsions, or mixtures of surface and internalimage emulsions are used as described in Luckey et al., U.S. Pat.2,996,382.

The silver halide emulsions are unwashed or washed to remove solublesalts. In the latter case, the soluble salts are advantageously removedby chill-setting and leaching or the emulsion is advantageouslycoagulationwashed, e.g., by the procedures described in Hewitson et al.,U.S. Pat. 2,618,556; Yutzy et al., U.S. Pat. 2,614,928; Yackel, U.S.Pat. 2,565,418; Hart et al., U.S. Pat. 3,241,- 969; and Waller et al.,U.S. Pat. 2,489,341.

The emulsions are advantageously sensitized with chemical sensitizers,such as, with reducing agents; sulfur, selenium or tellurium compounds;gold, platinum or palladium compounds; or combinations of these.Suitable procedures are described in Sheppard et al., U.S. Pat.1,623,499; Walter et al., U.S. Pat. 2,399,083; McVeigh, U.S. Pat.3,297,447; and Dunn, U.S. Pat. 3,297,446.

Likewise, the silver halide emulsions advantageously containspeed-increasing compounds, such as, polyalkylene glycols, cationicsurface active agents and thioethers or combinations of these asdescribed in Piper, U.S. Pat. 2,886,437; Dann et al., U.S. Pat.3,046,134; Carroll et al., U.S. Pat. 2,944,900; and Goffe, U.S. Pat.3,294,540.

The photographic and other hardenable layers used in the practice of ourinvention are advantageously hardened by various organic or inorganichardeners, alone or in combination, such as, the aldehydes, and blockedaldehydes, ketones, carboxylic and carbonic acid derivatives, sulfonateesters, sulfonyl halides and vinyl sulfonyl ethers, etc.

The photographic emulsions and elements described in the practice of ourinvention advantageously contain various colloids alone or incombinations as vehicles, binding agents and various layers. Suitablehydrophilic materials include both naturally-occurring substances, suchas. proteins, for example, gelatin, gelatin derivatives, cellulosederivatives, polysaccharides, such as, dextran, gum arabic and the like;and synthetic polymeric substances, such as, water-soluble, polyvinylcompounds like poly(vinylpyrrolidone), acrylamide polymers and the like.

The described photographic emulsion layers and other layers of aphotographicele'ment employed in the practice of our inventionadvantageously also contain alone or in combination withhydrophilic,Water-permeable colloids, other synthetic polymericcompounds, such as, dispersed vinyl compounds, such as, an latex formand particularly those which increase the dimensional stability of thephotographic materials.

Those photographic layers of the present invention are advantageouslycoated on a wide variety of supports. Typical supports include cellulosenitrate film, cellulose ester film, poly(vinylacetal) film, polystyrenefilm, poly- (ethvlene terephthalate) film. polycarbonate film andrelated films or resinous materials, as well as glass, paper,

14 metal and the like. Typically, a flexible support is employed,especially a paper support, which can be partially acetylated or coatedwith baryta and/or an alpha-olefin polymer, particularly a polymer of analpha-olefin containing 2 to 10 carbon atoms such as polyethylene,polypropylene, ethylenebutene copolymers and the like.

Spectral sensitizing dyes are used to confer additional sensitivity tothe light sensitive silver halide emulsion of the multilayerphotographic elements of the invention. For instance, additionalspectral sensitization can be obtained by treating the emulsion with asolution of a sensitizing dye as a final step or at some earlier stage.Sensitizing dyes useful in sensitizing such emulsions are described, forexample, in Brooker et al., U.S. Pat. 2,526,- 632, issued Oct. 24, 1950;Sprague, U.S. Pat. 2,503,776, issued Apr. 11, 1950; Brooker et al., U.S.Pat. 2,493,748; and Taber et al., U.S. Pat. 3,384,486. Spectralsensitizers which can be used include the cyanines, merocyanines,complex (trior tetranuclear) merocyanine, complex (trior tetranuclear)cyanine, holopolar cyanines, styryls. hemicyanine (eg., enaminehemicyanines), oxonols and hemioxonols.

Any of the color-forming couplers used in photographic elements are usedto advantage in our photographic materials. Included among the phenoland naphthol cyan-dyeforming couplers used to advantage are thosedescribed by the following U.S. Pats.: 2,423,730, 2,474,293, 2,521,-908, 2,725,291, 2,801,171, 3,253,294, etc. Included among theketomethylene yellow-dye-forming couplers used to advantage are thosedescribed in U.S. Pats. 2,298,443, 2,778,658, 2,801,171, 2,875,057,3,253,924, 3,277,155, etc. Included among the S-pyrazolonemagenta-dye-forming couplers used to advantage are those described inU.S. Pats. 2,600,788, 2,801,171, 3,252,924, etc.

Dispersing agents for color-forming couplers and the dispersingtechniques used to advantage include those set forth in Jelley et al.,U.S. Pat. 2,322,027; Mannes et al., U.S. Pat. 2,304,940; Fierke et al.,U.S. Pat. 2,801,171, etc.

The light-sensitive silver halide emulsion layers are arranged on thesupport of a multicolor element in any order; however, in an especiallyadvantageous arrangement, the red-sensitive layer is coated nearest thesupport, with the green-sensitive layer and the blue-sensitive layerover the red-sensitive layer in that order. Hydrophilic colloidinterlayers between the light-sensitive layers, light-filtering layers,etc. are used to advantage.

The photographic layers used in the practice of this invention arecoated by various coating procedures including dip coating, air knifecoating, curtain coating or extrusion coating using hoppers of the' typedescribed in Beguin, U.S. Pat. 2,681,294. If desired, 2 or more layersmay be coated simultaneously by the procedures described in Russel, U.S.Pat. 2,761,791 and Wynn, British Pat. 837,095.

Our compounds of Formulas I and II are advantageously used as silverbleaching agents in bleach baths for converting developed silver saltsin color-developed photographic elements, such as, those described inMannes et al., U.S. Pat. 2,252,718, Jelley et al., U.S. Pat. 2,322,027,VanCampen, U.S. Pat. 2,956,879 and Carroll et al., U.S. Pat. 2,944,900.A typical bleach solution of our invention comprises from about 0.01mole/l. to about 1.0 mole/ 1., preferably in the range of from about0.05 to about 0.5 mole/l. of our compounds of Formulas I and II andadvantageously contains addenda for adjusting the pH, e.g., an alkali(e.g., alkali metal hydroxides, etc.), an acid (e.g., sulfuric acid,phosphoric acid, acetic acid, citric acid, phthalic acid, etc.) toadjust the pH to a value in the range of from about 1.0 to about 6.5and, preferably, in the range from about 1.5 to about 4.0, and acid saltto buffer the solution (e.g., alkali metal acid phthalate, alkali metalacid phosphate, alkali metal bisulfate, etc.), a water softening agent(such as, an alkali metal hexametaphosphate), an alkali metal bromide inconcentrations from about .01 to about 3 moles/l. or a silver ioncomplexing agent, such as a 4-methy1imidazolinethione (e.g.,4-methylimidazolinethione), an alkali metal thiocyanate (e.g., sodiumthiocyanate, potassium thiocyanate, etc.), thiourea, etc. Silver ioncomplexing agents are advantageously used at concentrations of 0.01mole/l. and above.

The following examples are included for a further understanding of ourinvention:

EXAMPLES 1-5 Five samples of an unexposed, supported single-layergelatinous silver halide emulsion coating containing a cyan-dye-formingcoupler are processed under red light at a temperature of 21 C. in aprocess comprising subjecting the samples to an aqueous prehardeningbath comprising 2 percent succinaldehyde for a period of two minutes,water washing for five minutes, treating with a color developercontaining a pphenylenediamine color developing agent for a period ofninety minutes to assure complete, uniform fogging development resultingin optimum levels of silver and cyan dye, then water washing for aperiod of thirty minutes, fixing for a period of twenty minutes,employing the composition specified in Table VIII, below:

TABLE VIII Ingredient:

Sodium thiosulfate Concentration Sodium sulfite, desiccated 240.0 grams.Acetic acid, 28% 15.0 grams. Boric acid 48.0 cc. Potassium alum 7.5grams.

Water to make, 1.0 liter. 15.0 grams.

water washing and drying. Meanwhile, five bleach solutions are prepared,each of which contain 18.6 grams of the silver ion complexing agent4-methylimidazolinethione, 1 liter of Water and a bleaching agent in anamount shown in Table IX, below:

The pH of each bleach solution is 2.0 at a temperature of 23 C. Thebleach solutions of Examples 1, 3 and 4 are adjusted to the desired pHwith water, sodium hydroxide and sulfuric acid, respectively. Samples ofthe coatings processed in the manner previously described are partiallyimmersed into the bleach solutions of Examples 1, 2, 3, 4 and 5 forperiods of time ranging from: 2%. to 60 minutes in the bleach solutionsof Examples 1 and 2; 1 to 40 minutes in the bleach solution of Example3; seconds to 15 minutes in the bleach solution of Example 4; and 15seconds to 5 minutes in the bleach solution of Example 5. Upon removalfrom each bleach solution, the samples are washed with water for 30minutes and dried. Each of the five solutions bleaches the silver in theprocessed samples in proportion to the time of immersion. The density ofthe cyan dye image in the bleach samples is essentially unaffected. Theaminomethylquinone bleaching agents are either in the acid salt orquaternized salt form in our acid bleach solutions so they do notpollute the air with toxic vapors as do prior art quinone bleachsolutions.

Similar results are obtained when Examples 1-5 are repeated usingequimolar amounts of other aminomethylquinones of Formulas I and II inplace of the aminomethyl quinones used in Examples 1-5, showing thatthey are useful bleaching agents for silver bleaches in colorphotography and do not have any detrimental effect on the image dyes.

EXAMPLE 6 A high-speed, gelatino silver bromoiodide emulsion which hasbeen panchromatically sensitized with a cyanine dye is divided into twoportions. One portion is coated as a control on a cellulose acetate filmsupport at a coverage of 4.94 g. of silver and 15.06 g. of gelatin perm2. To the other portion of the emulsion is added with intimate mixing0.15 g. of Compound No. 36 per mole of silver and the resulting emulsionis coated on another piece of the cellulose acetate film support at thesame silver and gelatin coating rates as the control. Two samples ofeach film coating are exposed on an Intensity Scale Sensitometer. Onesample of the control and one sample of the coating containing CompoundNo. 36 are processed for five minutes in a developer solution having thecomposition:

. I G- p-Aminophenol sulfate 2.5 Sodium sulfate, desiccated 30.0Hydroquinone 2.5 Sodium metaborate octahydrate 10.0 Potassium bromide0.5

Water to make, 1.0 l.

unit.

EXAMPLES 7-22 The same procedure used for Example 6 is used in Examples7-22, but using other high-speed gelatino silver bromoiodide emulsions,other aminomethyl quinone compounds of our invention at the coatingrates and incubation times indicated in Table X. Each example has itsown control. The results of Examples 7-22, as well as Example 6, aresummarized in Table X.

TABLE X Compound Fog in density units Incubated Incu- Coating fog bationrate in 50% time Example Numg./mole Fresh RH, in number her Name ofAgfog49 C. weeks 6 47 2,3,5,6-tetramorpholinomethyl-p-quinone .15 .08 .47 2Control None 12 94 2 7...'.' 10 2.5-bis(morpholinomethyl)-p-quinone .09.11 .64. 2 Control None .14 1.09 2

8 12 2,5-bis(3-azabicycl0[3,2,2,]nonan-3-ylmethyl)-p- .09 .16 .43 2

quinone.

TABLE X-Continued v Compound Fog in density units Incubated Incu-Coating fog bation rate in 50% time Example Numg./mole Fresh BE, innumber ber Name of Ag fog 49 weeks Control None 14 1. 09

9-. 11 2,5-bis(pyrrolidinomethyl)-p-quinone 15 15 .34 2 Contr l None 1571 2 13 2,5-bis(N-oycl0hexyl-N-methylaminornethyl)-p- .09 16 1. 69 2quinone dinitric acid salt. Control None 14 1. 69 2 11 142,5-bis(dimethylaminomethyl)-p-quinone 15 17 50 2 Contr None 15 71 2 1216 2,5-bis(N-methylpiperidinium-methyl)-p- .3 .21 1

quinone dinierate. Control None 13 32 1 13 172,5-bls(N-methylmorpholiniummethyl)-p- .3 11 .21 1

quinone dinitrate. Contr l None 13 32 1 14 1s2,5-bis(N-methylpyrrolidiniummethyl)-p- .a .14 .32 1

quinone bis-p-toluenesulionate. Contro1 1 None 13 .32 1

15 20 2,5-bis(N,N-dimethyl-N-cyclohexylammonium- .3 12 .20 1

methyl) -p-quinone bis-p-toluene sulionate. Contr l None .13 .32 1

16 22 5-phenyl-fi-piperidinomethyl-o-quinone nitric- .15 .11 .36 2

acid salt. Contr l None 15 46 2 17 293,6-bis(morpholinomethyl)-4-phenyl-o-quinone 15 .13 .37 2

nitric acid salt. Contr l I None 15 46 2 18 303,6-bis(piperidinomethyl)4-phenyl-oquinone 11 .35 2

nitric acid salt. Control None 15 46 2 19 313,6-bis(pyrro1idinomethyl)-4-phenyl-o-quin0ne 15 .12 .31 2

nitric acid salt. Control I None 17 54 2 20 333,6431%?(piperidinomethyD-o-quinone nitric acid 12 13 24 1 so ControlNone 16 40 1 21.1. 34, 3,6-ls(morpholinomethyl)-0-quinone nitric acid 613 22 1 sa Control None 16 40 1 22 3,fi-bis(3-azabicyclo[3,2,2]-nonan-3-ylmethy1)-o- 12 19 .20 1

quinone nitric acid salt. Control None 16 1 The results obtained forExamples 6-22 show that in each We claim:

instance, the fog density for the incubated emulsion coatings containingour aminomethyl quinone compounds are substantially lower than therespective fog density for the incubated control emulsion coating. Inaddition to showing lower fog values in the incubated film coatingscontaining our compounds, fresh coatings of Compounds 36, 10, 17, 22,29, 30, 31, 33 and 34 also show lower fog values than the respectivecontrols. The results in Examples 622 illustrate the useful antifoggingcharacteristics of our aminomethyl quinone compounds in high-speed,silver bromoiodide emulsion coatings. Similar improvements are shownwhen the compounds used inExamples 6-22 and other aminomethyl quinonesof our invention are incorporated in one or more emulsion layers of amultilayer color film.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

1. A photographic silver halide emulsion containing a fog inhibitingagent selected from the class consisting of those having the formulas:

R1 (CHzA)n and v (II) 0 ll R represents a group selected from the classconsisting of an alkyl group, an alkenyl group and an aryl group; 1 Rand R each represent a group selected from the class consisting of analkyl group, an alkenyl group, an aryl group and the nonmetallic atomswhich when taken in combination with the nitrogen atom to which they areattached form a monovalent, heterocyclic group; R repree sents an alkylgroup; and X represents an anion; with the provision that each (CH A)group is substituted at a position ortho to an oxo group on the quinonering.

2. The emulsion of claim 1 wherein the fog inhibiting agent is selectedfrom those having the formula:

HzA

ACE

wherein A represents a group selected from the class con 4 sisting ofand 4. The emulsion of claim 2 wherein the fog inhibiting agent is2,5-bis(N-cyclohexyl-N-methylaminomethyl)-pquinone dinitric acid salt.

5. The emulsion of claim 1 wherein the fog inhibiting agent is selectedfrom those having the formula: 0 II (onus i V wherein R represents amember selected from the class consisting of hydrogen and a phenylgroup; n represents 1 or 2; and A represents a group selected from theclass consistingof 7. The emulsion of claim 5 wherein the fog inhibiting0 agent is 4-phenyl-G-piperidinomethyl-o-quinone nitric acid salt.

8. method for inhibiting fog in a photographic silver halide emulsionwhich comprises incorporating in saidv emulsion a fog inhibiting agentselected from the class consisting of those having the formulas;

and

OH2A)n wherein R represents a member selected from the class consistingof hydrogen, an alkyl group, an aryl group and a OHgA group; nrepresents an integer of from 1 to 3;

A represents a group selected from the class consisting of -NHR -HX N N-HX 1 5 and a -NR -X 21 R represents a group selected from the classconsisting of an alkyl group, an alkenyl group and an aryl group; R andR each represent a group selected from the class consisting of an alkylgroup, an alkenyl group, an aryl group and the nonmetallic atoms whichwhen taken in combination with the nitrogen atom to which they areattached form a monovalent, heterocyclic group; R represents an alkylgroup; and X represents an anion; with the provision that each --(CH A)group is substituted at a position ortho to an oxo group on the quinonering.

9. The method of claim 8 wherein said fog inhibiting agent is selectedfrom those having the formula:

consisting of:

wherein R and R when taken in combintion with the nitrogen atom to whichthey are attached form a monovalent, heterocyclic group and X representsan acid anion.

References Cited UNITED STATES PATENTS 3,396,022 8/1968 Dersch et a1.96109 3,161,506 12/1964 Becker 96-109 3,563,754 2/1971 Jones et al.96l09 3,449,122 6/1969 Kretchman et a1. 96109 NORMAN G. TORCHIN, PrimaryExaminer E. C. KIMLIN, Assistant Examiner US. Cl. X.Rt. 96-53

